On 12/06/2023 16.17, Alexandre Belloni wrote: > On 12/06/2023 14:30:18+0200, Rasmus Villemoes wrote: >> So testing this a bit more thoroughly reveals that the LBAT85/LBAT75 >> bits do not get updated immediately after the TSE bit is set; one needs >> to wait a little before the battery voltage detection is done and the SR >> bits updated. Unfortunately, the data sheet doesn't say anything about >> how long that might be or if there's some busy bit one could look at; >> all it says is actually exactly what I've done above: >> >> The battery level monitor is not functional in battery backup >> mode. In order to read the monitor bits after powering up VDD, >> instigate a battery level measurement by setting the TSE bit to >> "1" (BETA register), and then read the bits. >> >> IOW, please don't apply this patch until I figure out how to do this >> properly. >> > > The datasheet states 22ms for the temperature conversion so I would > expect it takes about that time. It's most likely much shorter than that - if I just busy-read SR until the LBAT bits are clear, that takes no more than 2ms, and the final read of SR still has the BUSY bit set, indicating a temp conversion being (still) in progress. But I'd prefer to have Renesas provide the proper value rather than using some seems-to-work-on-my-desk. But but, it's probably moot, see other reply. Rasmus
